A farmer got pulled over by state trooper Fred for speeding. The trooper lectured the farmer about his speed, and finally got around to writing out the ticket. As he was doing that he kept swatting at some flies that were buzzing around his head.
The farmer asked, "Having some problems with circle flies there, are ya?"
Trooper Fred stopped writing the ticket and said, "Well yeah, if that's what they are. I've never heard of circle flies."
So the farmer said, "Well, circle flies are common on farms. See, they're called circle flies because they're almost always found circling around the back end of a horse."
The trooper said "Oh," and went back to writing the ticket. Then after a minute he stopped and said, "Hey, did you just call me a horse's ass?"
"Oh no, officer," said the farmer. "I have too much respect for law enforcement and police officers to even think about calling you a horse's ass."
Trooper Fred said "Well, that's a good thing" and went back to writing the ticket.
After a pause, the farmer said, "Hard to fool them flies though."